#Rafter length table how to#

x Common Rafter ) Set the pivot of the DEWALT Rafter Square on the rafter edge. Let's now take a look at an example for laying out and cutting common hip, valley and jack rafters for a specific building width and roof rise, the roof is also to have an overhang.

#Rafter length table how to#

(See Figure A & B) EAVE LENGTH OF RAFTER FROM TABLEI MEASURING LINE HEEL CUT SEAT CUT DEDUCTION FOR RIDGE BOTTOM (BOTTOM PLUMB CUT) PLUMB CUT COMMON RAFTER LAYOUT WITH EAVE - FIGURE A TOP PLUMB LINEĤ Using DEWALT RAFTER SQUARE (continued) LENGTH OF RAFTER FROM TABLEI SEAT CUT DEDUCTION FOR RIDGE (NOTE MEASURIM+NG LINE IS ALONG TOP OF RAFTER) COMMON RAFTER LAYOUT WITH EAVE - FIGURE B TOP PLUMB CUT LINE The preceding paragraphs in this section describe how to use the Rafter Square for making plumb, seat and heel cuts, determining the length of a rafter, and were general in nature. Now mark a line from this point to the bottom of the square. Line up line A on the square with the bottom plumb cut line made and move the square along this line until the edge of the square reaches the rafter length point on the measure line.

To obtain the seat cut, construct another plumb cut line so that it crosses the measure line at the point that defines the rafter length. Seat Cuts The seat cut is made perpendicular to the bottom plumb cut (heel cut) where it intersects the measuring line at a distance from the original top plumb cut line, equal to the rafter length. (See Figure ) NOTE: For jack rafter lengths, refer to pages 0 thru. (See Figure ) Alter marking / the ridge thickness, mark another line, through this mark, parallel to the original top plumb cut line. Mark a line, along your protractor scale edge, on which you will measure and mark / your ridge thickness. Your protractor scale edge will now be 0 degrees to your plumb cut line. TOP END OF RAFTER 0 TOP PLUMB CUT LINE LINE A TOP PLUMB CUT LINE / RIDGE THICKNESS FICURE FICURE Simply line up A on the square so that it is coincides with the top plumb cut line you just made. A right angle line to the top plumb cut line is easily made with the The DEWALT Rafter Square. (See Figure ) LENGTH OF RAFTER FROM TABLE MEASURING LINE FIGURE DEDUCTION FOR RIDGE TOP PLUMB CUT MARKģ Using DEWALT RAFTER SQUARE (continued) The deduction of half the thickness of the ridge board is measured at right angles to the top plumb cut line and is marked parallel to the top plumb cut line. Therefore, half of the thickness of the ridge board should always be deducted from the listed rafter length before the top plumb cut is made. Note: The length of rafters obtained from tables are to the center of the ridge. Along the measuring line (refer to page ), lay out and mark the length on the rafter. Next, find the desired rise in inches per foot of run (slope), in the left hand column, and read the exact rafter length length required to the right of the rise, under the column for the type of rafter desired. First look up the required building width in Table.

Rafter Length FIGURE To find the length of a rafter (common, hip or valley) for a specific roof pitch and building width. (See Figure ) Illustration shows the square in position for marking the top plumb cut of a common rafter having a rise, also showing a ½' degree angle. While holding the pivot firmly against the rafter and keeping the number lined up properly, mark your line, starting at the pivot point along the top edge of the square.

Pivot the square so that the number ( rise) on the common scale lines up with the rafter. ) Extra wide, fixed base ) Extra thick body ideal for use as a saw guide ) ¼ spaced notches for marking out scribing lines ) Common rafter conversion chartĢ Using the DEWALT RAFTER SQUARE Place the square on the face of the rafter, near the top end of the rafter. ) Inch Scale -¾' long graduated every / inch. Description INCH SCALE PROTRACTORSGALE COMMON/JACK HIP-VAL BACK OF RAFTER SQAURE CONVERSION CHART FIXED BASE Features ) Common/Jack and Hip/Valley rafter scales-defined by inch rise per foot of run. 1 THE DEWALT RAFTER SQUARE The DEWALT Rafter Square is designed to provide a quick, accurate, and repeatable means for laying out and cutting the various cuts on common, hip, valley and jack rafters used in root construction.